yeah you can harassment is harassment whether it's on the internet or to your face
just make sure you keep the messages as proof & don't react to her
good luck
Absolutely. However, it would help to have proof. If she is sending you e-mails, print them out and collect them. Also print out any IM/ online messages you get. also, if she has myspace/facebook pages with anything bad about you or posts on your page, print those out. all of this is enough to get a restraining order on her. This order also includes virtual interactions. So if she continues to harass once the order has been made, you can then press charges and have her arrested.
Keep copies of the emails and file a report with the police. If she is threatening bodily harm, I believe you can have her charged. Copies of the emails or other communications will be needed as evidence.
I like what a previous responder said. Make sure you are not retaliating through the emal making your own threats and harrassment. Otherwise, you may end up in trouble yourself!
Yes. Sometimes people will look at you weird when you try to charge somebody from Internet threats. However, as long as you can prove it is her doing it you can press charges against her.